$ 21.6 \div 0.3 $
Answer: ${0}$ ${3}$ ${2}$ ${1}$ ${6}$ $\text{Shift the decimal 1 to the right.}$ ${2}$ $\text{How many times does }3\text{ go into }{2}\text{?}$ ${0}$ ${2}$ $-\vphantom{0}$ ${2}\div3={0}\text{ or }3\times{0} = {0}$ ${1}$ $\text{How many times does }3\text{ go into }{21}\text{?}$ ${7}$ ${2}$ ${1}$ ${0}$ $-\vphantom{0}$ ${21}\div3={7}\text{ or }3\times{7} = {21}$ ${6}$ $\text{How many times does }3\text{ go into }{6}\text{?}$ ${2}$ ${6}$ ${0}$ $-\vphantom{0}$ ${6}\div3={2}\text{ or }3\times{2} = {6}$ $21.6 \div 0.3 = 72$